Mount Baker

Legend

Volcano Map Legend

The sizes of symbols scale with earthquake magnitude, and their color with either the age of the earthquake or its depth, as shown in the legend below, and selected in the Control Panel. Clicking on an earthquake symbol shows its basic information and a link to a page with more details about the individual earthquake.

Stations

Control Panel

Volcano Map Panel

Using the tools in this panel you can control the earthquakes shown on the map. The minimum magnitude to plot is selected by the slider. The "Time" and "Depth" determines whether earthquake age or depth are used to color the symbol.

All

betweenand

All

fromto

Within:

(Km) of Mount Baker

All

betweenandkm

Sort by

DateMagLat

Limit *

records

*To reduce render time, queries have the following limits.

Format

Limit

XML/RSS

1000

Map

10000

CSV

10000

HTML

No limit

Magnitude

Measure of the energy released in an earthquake, obtained from interpretation of seismograms. For technical reasons several different magnitude scales are in common use. At PNSN we use the following: Md (Duration Magnitude) - based on the duration of shaking. Ml (Local Magnitude) - based on the peak amplitudes of high frequency seismograms, and Mw (Moment Magnitude) - based on matching waveforms of the lowest frequency ground motions in broad-band seismograms. More information at: http://earthquake.usgs.gov/earthquakes/glossary.php#magnitude and http://neic.usgs.gov/neis/phase_data/mag_formulas.html

(Origin) Time

Date and Time when the earthquake rupture initiated. Large earthquake ruptures can take many seconds to finish. Seismologists usually use Grennwich Mean Time (GMT) to avoid confusion ariasing from mixing observations from different time zones. However, the local time is also given as a reference for what local residents experience.

Coordinates

Location in geographic coordinates (as Latitude, Longitude in decimal degrees) of the position on Earth's surface directly above where an earthquake rupture initiated. PNSN coordinates are referenced to the WGS84 ellipsoid.

Depth

Depth within the Earth where an earthquake rupture initiated. PNSN reports depths relative to sea level, so the elevation of the ground above sea level at the location of the epicenter must be added to estimate the depth beneath the Earth's surface.

Number of Phases

Number of P and S arrival-time observations used to compute the hypocenter location. In general, more arrival-time observations result in improved earthquake locations.

RMS Misfit

How well the given earthquake location predicts the observed phase arrivals (in seconds). Smaller misfits mean more precise locations. The best locations have RMS Misfits smaller than 0.1 seconds.

Azimuthal Gap

A measure of how well network seismic stations surround the earthquake. Measured from the epicenter (in degrees), the largest azimuthal gap between azimuthally adjacent stations. The smaller this number, the more reliable the calculated horizontal position of the earthquake.

Last
events
10
km from summit

Mount Baker is an ice-clad volcano in the North Cascades, located about 50 kilometers E of Bellingham, WA. After Mount Rainier, it is the most heavily glaciated of the Cascade volcanoes.

Deposits which record the last 14,000 years at Mount Baker indicate that it has not had highly explosive eruptions like those of Mount St. Helens or Glacier Peak, nor has it erupted frequently. Historically, the most destructive and frequent events at Mount Baker have been debris flows and avalanches, some of which coincided with eruptive activity. The USGS provides a very Open File hazard assesment report by Gardner et. al., 1995. Heat flow and fumarolic activity became elevated in 1975, but were not accompanied by any other changes.

Background Seismicity

The PNSN operates 2 seismometers on or near Mount Baker. On average, we locate 1 to 2 earthquakes within 10 km of the volcano each year. We also often record seismic events related to glacier motion, and less frequently those related to rock-fall or ice/snow avalanches. See the seismicity page for a summary of ten years of events at Mount Baker.

Seismicity (Mount Baker)

Decadal Seismicity

Below you will find an epicenter map and time-depth plot for a region around Mount Baker for the decade, approximately 2001 - 2012 that shows typical or background levels of earthquakes in this region. Note, that only some of the earthquake locate right at the volcano. Other seismicity is 20 km to the southwest of the volcano. Just off the map to the northwest is a very active area with several swarms of events in the Demming, WA area. While there has been only one seismograph located right at the volcano there are several very sensitive ones not too far away such that the regional seismic network can reliably detect and locate earthquakes of magnitdue 1.2 and greater in this area. Smaller earthquakes could occur without being detected.

Map Guide:

Red dots represent events occuring in the last month of the decade.

Green dots represent events occuring in the last year, but more than a month ago.

Mount Baker has many active glaciers on it, many of which generate seismic signals when they move. Some of the plotted events above may be due to these glacier sources rather than true earthquakes. Because of the strong dispersion of seismic waves in the geologically complex rock of a volcano seismic sources at or very near the surface are hard to discriminate from real earthquakes at shallow depths.